Month: August 2005

前兩年考 LPI Level 1 的時候找到的模擬試題網站,對考試很有幫助.

• LPI – Exam Emulation
• LPI 101 Certification Practice Test
• LPI 102 Certification Practice Test
• ICE:ICE(home)

ICE 那個好像已經失效了,現在連結到 IBM 自己的認證中心…. @_@”

昨天的RFMaintainer 的 statechart並沒有實作部份,今天補上…
你可以看到這些都是寫在 Form 裡面,並沒有跟 UI 切開….
這就是我疑問的地方…
不過對照圖之後,你會發現這樣的寫法很清楚…不會有補東牆挖西牆,東改一塊西改一塊的問題…

		#region State Chart Implementation.
private int _StateVariable = 0;
private int _StateVariable_A = 0;
private int _StateVariable_B = 0;
private int _StateVariable_C = 0;
/// 

/// State 1: Transient
/// 
private void go_state_1()
{
_StateVariable = 1;
if( txtConnectString.Text == "" )
go_state_2();
else
go_state_3();
}
/// 

/// State 2: Connection string null
/// 
private void go_state_2()
{
_StateVariable = 2;
// disable controls.
radioButton1.Enabled = false;
radioButton2.Enabled = false;
dtpFrom.Enabled = false;
dtpTo.Enabled = false;
cboType.Enabled = false;
txtPath.Enabled = false;
btnBrowse.Enabled = false;
btnExport.Enabled = false;
}
/// 

/// State 3: Connection string not null
/// 
private void go_state_3()
{
_StateVariable = 3;
// enable controls.
radioButton1.Enabled = true;
radioButton1.Checked = true;
radioButton2.Enabled = true;
cboType.Enabled = true;
txtPath.Enabled = true;
btnBrowse.Enabled = true;
go_state_4();
go_state_7();
go_state_10();
}
/// 

/// State 4: Region A: Transient
/// 
private void go_state_4()
{
_StateVariable_A = 4;
if( radioButton2.Checked )
go_state_5();
else if( radioButton1.Checked )
go_state_6();
}
/// 

/// State 5: Region A: "Period" checked
/// 
private void go_state_5()
{
_StateVariable_A = 5;
dtpFrom.Enabled = true;
dtpTo.Enabled = true;
}
/// 

/// State 6: Region A: "All" checked
/// 
private void go_state_6()
{
_StateVariable_A = 6;
dtpFrom.Enabled = false;
dtpTo.Enabled = false;
}
/// 

/// State 7: Region B: Transient
/// 
private void go_state_7()
{
_StateVariable_B = 7;
if( txtPath.Text == "" )
go_state_8();
else
go_state_9();
}
/// 

/// State 8: Region B: "output file" null
/// 
private void go_state_8()
{
btnExport.Enabled = false;
}
/// 

/// State 9: Region B: "output file" not null
/// 
private void go_state_9()
{
btnExport.Enabled = true;
}
/// 

/// State 10: Region C: "Export type" is XML
/// 
private void go_state_10()
{
_StateVariable_C = 10;
cboType.SelectedIndex = 0;
}
/// 

/// State 11: Export
/// 
/// 
private void go_state_11()
{
}
#endregion
#region UI independence routines
/// 

/// I don't consider this button in State chart.
/// And I am lazy to change....
/// 
/// 
private bool testConnection( string connectString )
{
}
private bool export( int type, DateTime dtFrom, DateTime dtTo, string outputFile )
{
}
#endregion
#region Event handler
private void btnExport_Click(object sender, System.EventArgs e)
{
int iType = 0;
if( radioButton1.Checked == true )
iType = 1;
else if( radioButton2.Checked == true )
iType = 2;
if( export( iType, dtpFrom.Value, dtpTo.Value, txtPath.Text ) )
MessageBox.Show( "Finished!" );
else
MessageBox.Show( "Fail!!" );
}
private void btnBrowse_Click(object sender, System.EventArgs e)
{
// Displays a SaveFileDialog so the user can save the Image
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.Filter = "XML file|*.xml";
saveFileDialog1.Title = "Save to XML File";
saveFileDialog1.ShowDialog();
saveFileDialog1.OverwritePrompt = true;
// If the file name is not an empty string open it for saving.
if(saveFileDialog1.FileName != "")
{
txtPath.Text = saveFileDialog1.FileName;
}
}
private void btnTest_Click(object sender, System.EventArgs e)
{
testConnection( txtConnectString.Text );
}
private void radioButton1_CheckedChanged(object sender, System.EventArgs e)
{
go_state_6();
}
private void radioButton2_CheckedChanged(object sender, System.EventArgs e)
{
go_state_5();
}
private void txtPath_TextChanged(object sender, System.EventArgs e)
{
go_state_7();
}
private void txtConnectString_TextChanged(object sender, System.EventArgs e)
{
go_state_1();
}
#endregion
}

看Constructing the user interface with statecharts之後,應用到自己的小程式上…
書上建議先大致勾勒出畫面,然後寫出 screen rule.
我的畫面:

而 screen rule 大致如下:
*”Connection string” must be specified.
*如果”Connection string” is not specified, “All”, “Period”, “From”, “To”, “Export type”, “output file”, “browse”, “export” 都會被 disable.
*當按下 “Export” button 會開始進行 export 動作.
*當按下 “Browse” button 可以指定 output file
*如果 output file 未指定, “Export” 按鈕無法被 click.
*選擇 Option “All”, Option “Period” will be disabled.
*選擇 Option “Period”, Option “All” will be disabled.
*Export type 目前只有一個可以選擇: XML
所以,可以導出這樣的 statechart,只是不知道對不對…

最後寫 code 的時候,我為每個 state 加上編號,如圖:

然後再寫,的確是比較容易寫 code, 也比較容易了解.
只是,看來並沒有跟 UI 分離,或許是我自己理解錯誤…